Weft feeler mechanism

ABSTRACT

A rocking-type weft feeler mechanism wherein the weft feeler is arranged to reciprocate intermittently and periodically parallel to the cloth-fell from picking to picking.

United States aem Sakamoto 51 May 15, 1973 [54] WEFT FEELER MECHANISM[56] References Cited [75] Inventor: Toemon Sakammo, Hamamatsu-shi,UNITED STATES PATENTS Skizuoka-ken, Japan Assignee: Enshu Limitednamanwgun 2,819,737 1/1958 Opletal ..139/37O Shizuoka-ken, Japan PrimaryExaminerHenry S. J audon 1 Filedi 1971i Attorney-Henry N. Paul et a1.

[21] App1.No.: 208,243

[57] ABSTRACT [52] U.S. Cl. ..!.39/370 A rocking-type weft feelermechanism wherein the [51] Int. Cl. ..D(!3d 51/34 weft feeler isarranged to reciprocate intermittently [58] Field of Search ..139/336,370, 372, and periodically parallel to the th f 11 f picking 139/373 topicking.

14 Claims, 14 Drawing Figures PATENTEDHAYTBIHB SHEU 1 [IF 9 PATENTEUHIYI51915 3'. 732,900

SHEET 5 [IF 9 ONE COMPLETE I CRANK ROTATION TI T2 T3 T4 I 0IIIIIIIIIIIIIIIIIIIIIUIIIIIIIIIIIIIIUIIIIIIIIIIIIIIIIII PATENTEUHAY 151975 ,7 2,

sum 1 or 9 PATENTED 3,732,900

SHEET 8 BF 9 WEFI FEELER MECHANISM The present invention relates'to animproved weft feeler mechanism, and more particularly relates to animproved weft feeler mechanism of the weft feeler rocking type.

In the conventional rocking-type weft feeler mechanism, the weft feeleris carried by a rocking arm directed towards the cloth-fell from anoperator shaft mounted on the loom framework with the feeler extendingtransverse to the width of the woven fabric. At every picking motion,the rocking arm swings vertically about the axis of the operator shaftand the weft feeler advances into or recedes out from the warp sheet inthe vicinity of the cloth-fell so as to sense possible mispicking duringthe weaving process. In this warp sheet piercing motion of the weftfeeler, it is empirically known that the weft feeler tends to flip thejust inserted weft when it recedes upwards out of the warp sheet and alocal weft slack is formed at the pierced point thereby. Because theweft feeler pierces the warp sheet at points aligned along the fabriclength, successive formation of the above-mentioned local weft slacktends to form an undesirable warp stripe mark running along the fabriclength, degrading the quality of the woven product.

The object of the present invention is to provide an improved weftfeeler mechanism capable of carrying out the weft feeling action withoutformation of the warp stripe mark.

In order to attain this object, the improved weft feeler mechanism ofthe present invention is provided with means for reciprocating the weftfeeler periodically and intermittently parallel to the cloth-fell over aprescribed range.

This reciprocating means may reciprocate the operator shaft axially,render the rocking arm slide reciprocatingly along the operator shaft,render the rocking arm reciprocally and horizontally swing with respectto the operator shaft or render the weft feeler to move reciprocallywith respect to the rocking arm.

Further features and advantages of the present invention will be madeapparent from the following descrip tion, reference being made to theaccompanying drawings, wherein;

FIG. 1 is a perspective view of the conventional weft feeler mechanismof the rocking-type,

FIG. 2 is a perspective view of the first embodiment of the weft feelermechanism of the present invention,

FIG. 3 is a sectional part view of the arrangement shown in FIG. 2,

FIGS. 4A and 4B are front and spread views of the cylindrical cam usedin the arrangement shown in FIG.

FIG. 5 is a front view of main part of the second embodiment of the weftfeeler mechanism of the present invention,

FIG. 6A is a block diagram of the electric system used for thearrangement shown in FIG. 5, and FIG. 6B is a diagram for showing thetransformation of signals in the electric system shown in FIG. 6B,

FIG. 7 is a perspective view of the third embodiment of the weft feelermechanism of the present invention,

FIG. 8A is a perspective view of the fourth embodiment of the weftfeeler mechanism of the present invention,

FIG. 8B is a sectional part view of the arrangement shown in FIG. 8A,

FIG. 8C is a schematic plan view of the link parallel mechanism used inthe arrangement shown in FIG. 8A,

FIG. 9 is a front view of the main part of the fifth embodiment of theweft feeler mechanism of the present invention,

FIG. 10 is a perspective view of the sixth embodiment of the weft feelermechanism of the present invention.

Referring to FIG. 1, the arrangement of the conventional rocking-typeweft feeler mechanism is shown with related parts of the weaving system.In the system, a weft 2 is inserted into a shed formed by opened upperand lower warp sheets 1 and is beaten-up against a cloth-fell 3 of awoven fabric 4 by a reed (not shown) as in the usual weaving process.The woven fabric 4 is advanced for winding into a roll passing incontact over a breast-beam 6.

The weft feeler mechanism comprises an operator shaft 7 runningtransverse to the fabric 4 in parallel to the cloth-fell 3 and both endsthereof are supported by bearings held in laterally directed brackets80, 8b which are fixed to the breast-beam 6. On the left in the drawing,a collar 9 is fixed to the operator shaft 7 so as to restrict free axialmovement of the shaft 7. On the opposite end of the shaft 7, an operatorarm 11 is fixedly mounted, at its boss end on the shaft 7. The other endof the arm 11 is mechanically connected to the main shaft (not shown) ofthe loom via a linking rod 12..Near the midpoint of the shaft 7, arocking arm 13 is keyed to the shaft 7 at its boss end and at its freeend is provided with a laterally projecting pin 14. A boss 16 isturnably inserted over this pin 14. This boss 16 carries a feeler 17directed towards the fabric surface and an eIectro-conductive contactpin 18 projecting therefrom substantially at right angles to the feeler17. A spring 19 is mounted on the pin 14 in a disposition such as tourge the feeler 17 and the contact pin 18 in the counterclockwisedirection in the drawing. In the vicinity of the lateral pin 14, therocking arm 13 carries an electro-conductive contact piece 21 fixed tothe side face thereof. The contact piece 21 is connected to an auxiliaryelectric circuit (not shown), which functions to stop the loom running,via a connection 22. The contact pin 18 is connected to the electriccircuit via a connection 23. Both contact pin 18 and contact piece 21are electrically insulated from the rocking arm 13.

The above-mentioned electric circuit is designed as follows. Electriccurrent flows to the contact piece 21 at the moment when the crank angleis at several tens of degrees past the heating-up position. When thecontact pin 18 is in contact with the contact piece 21, the electriccircuit is so energized as to stop the loom running. If there is nocontact between the pin 18 and the piece 21 at this moment, the electriccircuit does not function.

As mentioned already, the operator arm 11 is mechanically connected tothe main shaft of the loom via the linking rod 12 so that the arm 11swings in synchronism with the cyclic rotation of the loom main shaft.Because the rocking arm 13 is rigidly connected to the operator arm 11via the operator shaft 7, the feeler 17 rocks up and down in synchronismwith the up and down swinging of the rocking arm 13 so that the point ofthe feeler l7 recedes upwards from the warp sheet at the upward swingingof the arm 13 while it advances into the warp sheet near the cloth-fell3 at the downvances into the warp sheet at a position between thecloth-fell 3 and the weft 2 and turns clockwise in the drawing about thepin 14 being beaten-up to the clothfell 3 with the weft 2 inserted. Bythis turning, the contact pin 18 is disengaged from the contact piece21. After the beating-up motion, the reed resumes its recededdisposition while the feeler 17 is retained at its turned dispositionbeing caught by the beaten-up weft 2 and the contact pin 18 is retainedremote from the contact piece 21. At about this moment, electric currentflows to the contact piece 21 but the electric circuit is not energizedby this electric current because of the absence of contact between thepin 18 and the piece 21, whereby the loom carries on its running withoutinterruption.

Following the stop of the electric current flow to the piece 21, feelerl7 recedes from the warp sheet so as to stand by for the next beating-upmotion. When the weft is not inserted or weft breakage takes place,feeler 17 is not pressed to cloth-fell 3 by weft 2 and feeler 17 turnscounterclockwise in the drawing due to the spring force of the spring19. This counterclockwise turning of feeler 17 causes pin 18 to makecontact with piece 21 and the electric circuit is closed so as to stopthe running of loom.

In the case of the above-explained weft feeling system, the feeler 17pieces, at every picking cycle, locations which lie in a alignment alongthe fabric length. At the time of the upward escape from the warp sheetduring the weft feeling cycle, the feeler 17 tends to repel the weft,thereby creating a slack of the weft in the fabric construction. Asuccession of such slack portion forms a kind of elongated stripe mark24 on the fabric surface, thereby degrading the quality of the resultantproducts.

In consideration of the fact that the aligned succession of the pointspierced by the feeler 17 causes formation of the stripe mark 24, theinventional art is based on the concept that the piercing points changeperiodically transverse to the fabric width substantially in parallel tothe cloth-fell line from pick to pick.

In FIG. 2 the first embodiment of the feeler mechanism of the presentinvention is shown, wherein an actuator cam is utilized so as to causeperiodical reciprocating of the feeler transverse to the fabric width.In the drawing, elements similar to the elements used in the arrangementshown in FIG. 1 are designated by similar reference numerals andstructural explanation of the same is somewhat simplified.

One end of the operator shaft 7 is rotatably supported by the bracket 8ain an axially slidable disposition with omission of the end collar 9.The other end part of the shaft 7 is elongated sideways rotatably andaxially slidable through the bracket 8b of the structure hereinafterdescribed. Outside the bracket 8b, a cylindrical cam 101, a brake drum102 and a ratchet wheel 103 are rotatably mounted on the shaft 7 formingone body. Their anial movement is limited by collars 104 and 106 fixedlymounted on shaft 7 on both sides of the one body. On the outer end ofshaft 7, an operator arm 11 is fixedly mounted with a linking rod 12disposed at its free end for connection to the loom main shaft (notshown).

An ordinary universal joint 107 is used for connection of ann 11 withrod 12 so as to enable the transmission of movement from loom main shaftto shaft 7 even under the axial reciprocation of shaft 7, which will beexplained later in detail.

The composition and structure of the rocking arm 13 and its relatedparts are the same as those of the mechanism shown in FIG. 1.

A small lever 108 is pivoted to a lateral pin 109 fixed to the stem ofthe operator arm 11 one end of which pivotally carries a pawl 112 via alateral pin 111. A spring 113 is mounted on the pin 111 so that thepoint of the pawl 112 is urged into engagement with a tooth of theratched wheel 103. A spring 114 is mounted on the pin 109 so as to urgethe lever 108 counterclockwise in the drawing. An upright projection 116is formed integral with the stem of the arm 11 and is provided with astopper 117 for limiting the counterclockwise pivotation of the lever108 about the pin 109 by the spring 114. This stopper may be provided inthe form of an adjustable screw as shown in the drawing. On the oppositeside of the stopper 117 with respect to the pivotal center 109 of lever108, a bracket 118 is fixed to the breast-beam 6. A stopper pin 119projects laterally from bracket 118 so as to limit the counterclockwisepivotation of the lever 108 also.

A brake band 121 isdisposed partly embrasing the brake drum 102 withitsone end being fixed to the periphery of drum 102 and the other endbeing connected to the bracket 118 via a spring 122 and a pin 123. Thisbrake assembly functions to limit possible excess rotation of the cam101. The cam 101 is provided with a selectively curved peripheral camgroove 124 which receives a roll 126 rotatably carried by a hanger arm127. The hanger arm 127 forms an upper integral with the bracket 8b.

It should be noted that the three dimensional position of the roll 126remains unchanged even when the cam 101 rotates.

The above-explained arrangement will be better understood from theillustration given in FIG. 3.

The cam groove 124 of the cam 101 should be curved in the following way.The groove 124 runs endlessly over the cam periphery in such a mannerthat one tooth rotation of wheel 103 causes axial movement of cam 101over a distance corresponding to-a certain number of warps and severalteeth rotations of the wheel 103 cause an axial movement of cam 101 inthe opposite direction. Further, after one complete rotation, cam 101resumes its initial axial position. One typical example of the earn 101and the incorporated groove 124 is shown in FIGS. 4A and 4B.

The weft feeler mechanism of the above described structure operates inthe following way.

At the moment when the operator arm 11 swings upwards so as to advancethe feeler 17 into the warp sheet, the small lever 108 moves upwardsalso and the point of the pawl 112 slides over one tooth distance on thetoothed periphery of the ratchet wheel 103. During this upward movement,pivotation of lever 108 is limited by the stopper 117. At the momentwhen operator arm 11 swings downwards so as to make feeler 17 recedefrom the warp sheet, the small lever 108 moves downwards also andperform a counterclockwise pivotation so that pawl 112 turns ratchetwheel 103 through an angle of one tooth.

By this turning of ratchet wheel 103, the cam 101 turns through the sameturning angle because cam 101 and wheel 103 form one body. Because theroll 126 does not change its three dimensional position, this turningcauses a corresponding axial displacement of the cam 101. This axialdisplacement of cam 101 naturally induces same directional axialmovement of the operator shaft 7 and the accompanying feeler 17. In thisway, feeler 17 moves intermittently from pick to pick transverse to thefabric width. After several picks, because of the selectively designedcurvature of the cam groove 124, the axial movement of the cam 101, i.e.the transverse movement of the feeler 17, changes its direction. Owingto this intermittent, reciprocal and periodical movement of feeler 17,its piercing mark presents a wave-formed locus '128 and weft slackingcaused by one feeling action is compensated by the next beating-upmotion. In this way, the formation of the undesirable stripe mark 24 inthe conventional feeling technique can be effectively obviated.

In the embodiment shown in FIG. 2, the axial reciprocation of theoperator shaft 7 is effected by the swinging of the operator arm 11 viathe cylindrical cam 101. However, the driving sflufce of this axialreciprocation of the operator shaft 7 may be given in a different formalso. A modification of this sense is shown in FIG. 5.

Although omitted in the drawing, the rocking arm 13, the feeler l7 andtheir related parts are of similar construction to those of theembodiment shown in FIG. 2. Outside the bracket 8b, the arrangement ofthe members mounted on and related to the operator shaft 7 is almost thesame as that in the embodiment shown in FIG. 2.

In this embodiment, however, the brake drum 102 and its related partsare omitted and the ratchet wheel 103 is substituted for by a gear 151rotatably mounted on the operator shaft 7. This gear 151 is in a meshingengagement with a drive gear 152 firmly mounted on the rotational shaftof a pulse motor 153 fixed on the breast-beam 6.

Upon rotation of the cylindrical cam 101 actuated by the pulse motor 153via the gears 152 and 151, the reciprocation of the operator shaft 7 iseffected in the same manner as that in the embodiment shown in FIG. 2.Because the gear 151 must reciprocate horizontally together with theshaft 7 while retaining the meshing engagement with the gear 152 of thepulse motor 153, the axial length of the gear 152 must be longer thanthe entire stroke of the reciprocation of the gear 151.

The operational mode of the pulse motor 153 will hereinafter beexplained in detail, reference being made to the illustrations in FIGS.6A and 6B.

In FIG. 6A, an electric circuit for energizing the operation of thepulse motor 153 is shown in a blockdiagram whereas the change in thesignal form is shown in FIG. 68, wherein moment T corresponds to bottomcenter, T to back center, T to top center" and T to front center. Thepulse motor runs when the feeler is stationary after having receded fromthe warp sheet at the back center.

A series of square-pulses a are produced by a pulseoscillator 161 andfed to a gate-circuit 162. Separately from this, a suitable contactplate 163 is mounted on the crank shaft of the loom and a contact switch164 is mounted on the loom framework. As the contact plate 163approaches the contact switch 164, an output signal issues therefrom andis fed to the Schmitt-circuit 166. By processing in the Schmitt-circuit166, this signal is converted to a timing pulse b, which is fed to adifferentiation element 167. The output of the differentiation element167 in the form of trigger pulses c is then fed to aone-shot-multi-vibrator 168. An output pulse d of theone-shot-multi-vibrator 168 having a duration of t is then fed to thegate-circuit 162. The gatecircuit 162 issues a series of square-pulseoutput e over a period corresponding to the duration t of the pulse d.This output e is fed to a pulse-amplifier 169 for amplification. Theamplified output f of the pulse-amplifier 169 is then fed to the pulsemotor 153 so that the motor 153 runs over a period corresponding to thenumber of pulses from the amplifier 169.

Therefore, at every one rotation of the loom crank, a prescribed numberof pulses are fed to the pulse motor 153 so that the motor 153 runs overa prescribed of period for rotation of the cam 101.

As is clear from the above-description, the length of the motor runningperiod is equal to the duration t of the output pulse d from theone-shot-multi-vibrator 168. Therefore, the length of the motor runningperiod can be adjusted as desired by adjusting the time constant t ofthe vibrator 168. The running speed of the motor can be adjusted asdesired also by adjusting the amplitude of the pulses from thepulse-oscillator 161. Timing of the starting of the motor running isadjusted by selection of the position to mount the contact switch 164.The plate 163 can be given in any form as far as it operates insynchronism with rotation of the main shaft of the loom.

In the case of the foregoing embodiments, the operator shaft 7 ismounted for axial reciprocation so that the feeler 17 is moved parallelto the cloth-fell at every picking motion via the rocking arm 13 fixedlymounted on the operator shaft 7. However, in order to let the feeler 17move parallel to the cloth-fell, it is also allowable that the rockingarm 13 is mounted on the operator shaft 7 in an axially slidablearrangement while the operator shaft 7 is mounted stationarily.

An embodiment of this arrangement is shown in FIG. 7, wherein elementsin common with those in the first embodiment in FIG. 2 are designated bysimilar reference numerals.

As is seen in the drawing, the feeler 17 and its related parts are thesame as those in the first embodiment shown in FIG. 2. The axialmovement of the shaft 7 is limited by the collar 9 fixedly mountedthereon outside the bracket 8a. On the opposite end the operator arm 11is fixed at its boss end so as to cause the feeler rocking motion inresponse to the pikcing motion of the loom as in the conventionalmechanism shown in FIG. 1.

An elongated key 201 is attached at about the midpoint of the operatorshaft 7 and the boss of the rocking arm 13 is inserted over the shaft 7and the key 201 so that the arm 13 can slide in the axial directionalong the key 201. The boss of the rocking arm 13 has a tongue 202projecting forwardly and this tongue 202 carries a roll 203. Beingslightly spaced from the rocking arm 13, a supporter bracket 204 isfixedly inserted over the shaft 7 and carries a pulse motor 206 fixedthereto. The

supporter bracket 204 is provided with a forward projection 207 also,which rotatably carries a shaft 208 running substantially parallel tothe operator shaft 7. The shaft 208 fixedly carries a gear 209 at itsone end, which is in a meshing engagement with a drive gear 211 fixed tothe rotational shaft of the pulse motor 206. On the other end of theshaft 208, a cylindrical cam 212 having a peripheral cam groove 213 isfixedly mounted. The cam groove 213 receives the roll 203 carried by thetongue 202. The curvature of the cam groove 213 is designed in the samesense as that of the cam groove 124 in the first embodiment shown inFIG. 2 (see FIGS. 4A and 48 also). The pulse motor 206 is operated inthe same manner as the pulse motor 153 in the second embodiment shown inFIG. 5 (see FIGS. 6A and 68 also).

Following the rotation of the cam 212 caused by the pulse motor 206, therocking arm 13 is forced to move parallel to the cloth-fell 3 via theroll-cam groove engagement.

In the case of the third embodiment shown in FIG. 7, the rocking arm 13slides along the stationary operator shaft 7 parallel to the cloth-fell3. A modification of such arrangement is shown in FIGS. 8A and 83,wherein the rocking arm swings laterally about a pivotal point fixedrelative to the operator shaft 7.

Axial displacement of the shaft 7 is limited by a pair of collars 9a and9b fixed on the shaft 7 sandwiching the bracket 8a and angular movementthereof is effected by the linking rod l2 via the operator arm 11 as inthe case of the third embodiment. About the midpoint of the shaft 7, aholder bracket 231 is fixedly mounted. The bracket 231 is provided withan upper recess 232 running in the warp direction and receiving a slider233 therein. An upright pin 234 is planted on the slider 233 and one endof a rocking arm 6 is pivoted on the pin 234. The arm 6 carries thefeeler l7 and its related parts in the same manner as in the foregoingembodiments. On the other end of the holder bracket 231, an upright pin236 is planted pivotally carrying a small arm 237. The other end of thearm 237 is pivoted to the stem of the rocking arm 6 by a pin 238. Whenthe arm 237 swings horizontally about the pin 236, the rocking arm 6swings horizontally about the pin 234, whereby the feeler 17reciprocates parallel to the clothfell 3. This double swinging mechanismis called a link parallel mechanism and is schematically shown in FIG.8C. A connector rod 239 is at its one end connected to the small arm 237and at its other end to an arrangement for causing the swinging of thesmall arm 237 described as follows.

As is shown in detail in FIG. 8B, this arrangement includes a segmentgear 241 freely inserted over the operator shaft 7 and, at its upperportion, fixed to the outer face of the bracket 812. Further, outside ofthe segment gear 241, an upright holder 242 is fixedly mounted on theoperator shaft 7 and fixedly carries an upright stud 243 having astepped end portion 244. A horizontal bevel gear 246 is rotatablyinserted over the stud 243 in a meshing engagement with the segment gear241. A ratchet wheel 247 is rotatably inserted over the stepped endportion 244 of the stud 243 slightly spaced over the bevel gear 246. Anupright pin 248 is planted on the upper face of the bevel gear 246 and apawl 249 is at its one end pivoted on the pin 248. A spring 251 isdisposed to the pin 248 so as to urge the pawl 249 into a meshingengagement with the ratchet wheel 247 in such a manner that theclockwise rotation of the bevel gear 246 in FIG. 8A induces clockwiserotation of the ratchet wheel 247 via the pawl-ratchet engagement. Anupright pin 251 is planted on the upper face of the ratchet wheel 247,to which the outer end of the connector rod 239 is pivoted.

Upon angular rocking of the operator shaft 7 at every picking motion,the stud 243 swings to and fro also. Following this swinging of the stud243, the bevel gear 246 rotates clockwise and counterclockwise owing tothe meshing engagement with the segment gear 241. This rotation of thebevel gear 246 causes clockwise rotation of the ratchet wheel 247 viathe pawl-ratchet engagement. As the ratchet wheel 247 rotates in thismanner, corresponding axial movement is imparted to the connector rod239 so as to cause corresponding horizontal swinging of the rocking arm6 via the abovedescribed link parallel mechanism.

A modification of the embodiment using an electric system is illustratedin FIG. 9, wherein the mechanical arrangement inside the bracket 8b isalmost the same as that in the fourth embodiment shown in FIG. 8B withthe minor exception that the bracket 81; is sandwiched by the collars 9aand 9b.

A holder 281 is fixedly mounted on the operator shaft 7 and carries apulse motor 282 fixed thereto. A

circular disc 283 is fixedly mounted on the rotational shaft of thepulse motor 282. The connector rod 239 is pivoted, at its outer end, toan upright pin 284 planted near the fringe of the disc 283. The pulsemotor 282 is operated in the same manner as that in the secondembodiment shown in FIG. 5 and the third embodiment shown in FIG. 7.

At every rotation of the disc 283 over the prescribed rotation angle, acorresponding axial movement is imparted to the connector rod 239 sothat the rocking arm 6 swings horizontally via the link parallelmechanism.

In the foregoing embodiments, the reciprocation of the feeler 17accompanies the axial reciprocation of the operator shaft 7, the slidingof the rocking arm 13 along the operator shaft 7 or the swinging of therocking arm 13 about a pivotal point which is stationary with respect tothe operator shaft 7. In the embodiment shown in FIG. 10, neither theshaft 7 nor the arm 13 move parallel to the cloth-fell 3.

In the arrangement shown, the rocking arm 13 is fixedly mounted on theoperator shaft 7 at its boss end,

which is provided with a front tongue 301. A roll guide 302 is fixed onthe front tongue 301. The free end of the rocking arm 13 carries alaterally elongated pin 303 in an axially slidable arrangement. Angularrotation of the pin 303 is limited by a suitable key (not shown).

The feeler 17, the contact pin 18 and the spring 19 are disposed to thepin 303 in the same manner as the first embodiment shown in FIG. 2. Alaterally elongated contact piece 304 is fixed to the body of the arm 13and electrically connected to the auxiliary electric circuit (not shown)in the same manner as the foregoing embodiments by the connections 22and 23. On the other elongated side of the contact piece 304, a rollguide 306 is fixed. A collar 307 is fixedly inserted over the pin 303near the spring 19 and another spring 308 is disposed between the collar307 and the free end boss of the rocking arm 13 so as to urge the feeler17 away from the boss of the rocking arm 13. A rope 309 is fixed, at itsone end, to the free end of the pin 303 and,

at its other end, to mechanism for causing the reciprocation of thefeeler 17 via the roll guides 306 and 302 described as follows.

This mechanism includes a pair of upright stands 311 and 312 fixed onthe elongated end portion of the breast-beam 6, being spaced from eachother. The inner stand 311 rotatably carries a drum 313, on theperiphery of which one end of the rope 309 is fixed. The outer stand 312rotatably carries a ratchet wheel 314 and a crank arm 316 is formed bybending the rotational shaft of the wheel 314. The free end of the crankarm 316 is connected at a point on the side face of the drum 313 by alink rod 317. A projection 318 extends inwardly from the body of theoperator arm 11, carrying a pin 319. A pawl 321 is pivoted at its lowerend on the pin 319 and a spring 322 is disposed to the pin 319 so as tourge the pawl 321 in a meshing engagement with the ratchet wheel 314. Asuitable stopper is disposed to the ratchet wheel 314 so as to result inone way rotation of the wheel 314 only.

At every swing of the arm 11, the pawl 321 rotates the ratchet wheel 321over a prescribed rotation angle and this one way rotation of wheel 314causes two way reciprocal rotation of the drum 313 via the crank arm316. This two way reciprocal rotation of drum 313 induces reciprocalmovement of the feeler 17 parallel to the cloth fell 3.

EXAMPLE 1 ln order to confirm the effect of the present invention,weaving was carried out on two sets of looms, one being provided withthe conventional weft feeler mechanism and the other being provided withthe weft feeler mechanism of the present invention. The running speed ofthe looms was of 175 RPM, polyester-cotton blended yarns of 45 were usedfor warp, cotton yarns of 40 were used for weft, warp density was 80ends/inch and weft density was 60 picks/inch.

In the case of the conventional weft feeler mechanism, formation of thewarp stripe mark by weft detection was clearly observed when feelers ofdiameters larger than 0.5 mm used whereas, in the case of theinventional weft feeler mechanism, no formation of the mark was observedif the feeler diameter did not exceed 1.0 mm.

It is empirically known that the feeler can Withstand the impact attackduring the beating-up motion if its diameter is larger than 0.5 mm.Therefore, it can be justifiably concluded that the weft feelermechanism of the present invention can be employed in the actual weavingprocess without the danger of breakage.

EXAMPLE 2 The weft feeler mechanisms of the present invention were usedon five sets of weaving looms of 56 inch working width and 162 RPMrunning speed. Weaving was carried out for about 1,600 hours in totalusing warps of 34 and wefts of 34 thickness and the warp density was 103ends/inch while the weft density was 1 l2 pick/inch. I

Steel weft feelers, which is converged towards its point, of 0.3 mmnominal average diameter were used.

No formation of warp stripe marks were observed and only seven feelerbreakages were counted.

EXAMPLE 3 On the same looms, weaving was carried out for same length ofperiod as the foregoing example. Warps of 30/2 and wefts of 7 were used.Warp density was 104 ends/inch while weft density was 40 picks/inch.

Steel weft feelers of the converged type having a nominal averagediameter of 0.7 mm were used.

Neither breakages of the weft feelers and formation of warp stripe markswas observed.

In the case of the foregoing embodiments, operator shafts extendingtransverse the entire width of the woven fabric are mentioned. In thisconnection, however, the shaft may extend only over the range allowingthe reciprocation of the weft feeler. For example, the shaft may extendover half width of the woven fabric, being supported at one side of theloom only or being supported at the midway of the fabric only.

Further, rocking movement of the operator shaft may be caused by theto-and-fro motion of the lathe also.

What is claimed is:

1. An improved weft feeler mechanism comprising, in combination, anoperator shaft mounted parallel to the cloth-fell transverse to thewidth of the woven fabric, means for rocking said operator shaftangularly once at every picking motion, a rocking arm mounted onto saidoperator shaft at its boss end and directed towards the cloth-fell, aweft feeler disposed tothe free end of said rocking arm, means foractuating an auxiliary electric circuit for stopping the loom running inresponse to the detection of mis-pickings by said weft feeler and meansfor reciprocating said weft feeler periodically and intermittentlyparallel to the cloth-fell over a prescribed range.

2. An improved weft feeler mechanism claimed in claim 1, whereinreciprocation of said weft feeler is caused by the axial reciprocationof said operator shaft.

3. An improved weft feeler mechanism claimed in claim 2, wherein saidreciprocating means comprises a cylindrical cam mounted on said operatorshaft in a rotatable but axially non-displaceable disposition, a ratchetwheel rotatably mounted on said operator shaft forming a body with saidcylindrical cam a pawl disposed to said rocking means in meshingengagementwith said ratchet wheel and a fixed roll received in aperipheral cam groove of said cylindrical cam.

4. An improved weft feeler mechanism claimed in claim '2, wherein saidreciprocating means comprises a cylindrical cam mounted on said operatorshaft in a rotatable but axially non-displaceable disposition, a gearrotatably mounted on said operator shaft forming a body with saidcylindrical arm, a pulse motor for rotating said gear and an electricsystem for actuating said pulse motor.

5. An improved weft feeler mechanism claimed in claim 4, wherein saidelectric system comprises a pulseoscillator, a gate-circuit connected tosaid pulseoscillator and operating on said pulse motor, a contact switchperiodically operated in synchronism with the crank cycle, aSchmitt-circuit connected to said contact switch, a differentiationcircuit connected to said Schmitt-circuit and a one-shot-multi-vibratorconnected to said differentiation circuit at its output terminal.

6. An improved weft feeler mechanism claimed in claim 1, whereinreciprocation of said weft feeler is caused by the axial reciprocationof said rocking arm along said operator shaft.

7. An improved weft feeler mechanism claimed in claim 6, wherein saidreciprocating means comprises a pulse motor fixedly mounted on saidoperator shaft an axially non-displaceable disposition, cylindrical camdriven for rotation by said pulse motor, a roll fixed to boss saidrocking arms and received in a cam groove of said cylindrical cam and anelectric system for actuating said pulse motor.

8. An improved weft feeler mechanism claimed in claim 7, wherein saidelectric system comprises a pulseoscillator, a gate-circuit connected tosaid pulseoscillator and operating on said pulse motor, a contact switchperiodically operated in synchronism with the crank cycle, aSchmitt-circuit connected to said contact switch, a differentiationcircuit connected to said Schmitt-circuit and a one-shot-multi-vibratorconnected to said differentiation circuit at its input terminal and tosaid gate-circuit at its output terminal.

9. An improved weft feeler mechanism claimed in claim 1, whereinreciprocation of said weft feeler is caused by a horizontal swinging ofsaid rocking arm about said operator shaft.

10. An improved weft feeler mechanism claimed in claim 9, wherein saidreciprocating means comprises a holder bracket fixedly mounted to saidoperator shaft on which said rocking arm is pivoted at its one end, alink parallel mechanism mounted on said holder bracket connected withsaid rocking arm, a connector rod connected to said link parallelmechanism at its one end, a fixed segment gear freely inserted over saidoperator shaft, a holder fixedly mounted on said operator shaft, a bevelgear rotatably mounted on said holder in meshing engagement with saidsegment gear and an assembly mounted on said holder connected with theother end of said connector rod for converting rotation movement of saidbevel gear into axial reciprocation of said connector rod.

11. An improved weft feeler mechanism claimed in claim 9, wherein saidreciprocating means comprises a holder bracket fixedly mounted to saidoperator shaft on which said rocking arm is pivoted at its one end, alink parallel mechanism mounted on said holder bracket connected withsaid rocking arm, a connector rod connected to said link parallelmechanism at its one end, a pulse motor fixedly mounted to said operatorshaft, an assembly connected to said pulse motor and connected with theother end of said connector rod for converting rotation movement of saidpulse motor into axial reciprocation of said connector rod and anelectric system for actuating said pulse motor.

12. An improved weft feeler mechanism claimed in claim 11, wherein saidelectric system comprises a pulse-oscillator, a gate-circuit connectedto said pulseoscillator and operating on said pulse motor, a contactswitch periodically operated in synchronism with the crank cycle, aSchrnitt-circuit connected to said contact switch, a differentiationcircuit connected to said Schmitt-circuit and a one-shot-multi-vibratorconnected to said differentiation circuit at its input terminal and tosaid gatecircuit at its output terminal.

13. An improved weft feeler mechanism claimed in claim 1, wherein saidweft feeler reciprocates relative to said free end of said rocking arm.

14. An improved weft feeler mechanism claimed in claim 13, wherein saidreciprocating means comprises an assembly for mounting said weft feelerslidably on said free end of said rocking arm, a strand connected tosaid assembly at its one end, a rotatable drum fixed to the loomframework on the periphery of which the other end of said strand isfixed, a rotatable ratchet wheel mounted on said loom framework, a crankmechanism connecting said ratchet wheel with said drum and a pawldisposed to said rocking means in meshing engagement with said ratchetwheel.

1. An improved weft feeler mechanism comprising, in combination, anoperator shaft mounted parallel to the cloth-fell transverse to thewidth of the woven fabric, means for rocking said operator shaftangularly once at every picking motion, a rocking arm mounted onto saidoperator shaft at its boss end and directed towards the cloth-fell, aweft feeler disposed to the free end of said rocking arm, means foractuating an auxiliary electric circuit for stopping the loom running inresponse to the detection of mis-pickings by said weft feeler and meansfor reciprocating said weft feeler periodically and intermittentlyparallel to the cloth-fell over a prescribed range.
 2. An improved weftfeeler mechanism claimed in claim 1, wherein reciprocation of said weftfeeler is caused by the axial reciprocation of said operator shaft. 3.An improved weft feeler mechanism claimed in claim 2, wherein saidreciprocating means comprises a cylindrical cam mounted on said operatorshaft in a rotatable but axially non-displaceable disposition, a ratchetwheel rotatably mounted on said operator shaft forming a body with saidcylindrical cam a pawl disposed to said rocking means in meshingengagement with said ratchet wheel and a fixed roll received in aperipheral cam groove of said cylindrical cam.
 4. An improved weftfeeler mechanism claimed in claim 2, wherein said reciprocating meanscomprises a cylindrical cam mounted on said operator shaft in arotatable but axially non-displaceable disposition, a gear rotatablymounted on said operator shaft forming a body with said cylindrical arm,a pulse motor for rotating said gear and an electric system foractuating said pulse motor.
 5. An improved weft feeler mechanism claimedin claim 4, wherein said electric system comprises a pulse-oscillator, agate-circuit connected to said pulse-oscillator and operating on saidpulse motor, a contact switch periodically operated in synchronism withthe crank cycle, a Schmitt-circuit connected to said contact switch, adifferentiation circuit connected to said Schmitt-circuit and aone-shot-multi-vibrator connected to said differentiation circuit at itsoutput terminal.
 6. An improved weft feeler mechanism claimed in claim1, wherein reciprocation of said weft feeler is caused by the axialreciprocation of said rocking arm along said operator shaft.
 7. Animproved weft feeler mechanism claimed in claim 6, wherein saidreciprocating means comprises a pulse motor fixedly mounted on saidoperator shaft an axially non-displaceable disposition, cylindrical camdriven for rotation by said pulse motor, a roll fixed to boss saidrocking arms and received in a cam groove of said cylindrical cam and anelectric system for actuating said pulse motor.
 8. An improved weftfeeler mechanism claimed in claim 7, wherein said electric systemcomprises a pulse-oscillator, a gate-circuit connected to saidpulse-oscillator and operating on said pulse motor, a contact switchperiodically operated in synchronism with the crank cycle, aSchmitt-circuit connected to said contact switch, a differentiationcircuit connected to said Schmitt-circuit and a one-shot-multi-vibratorconnected to said differentiation circuit at its input terminal and tosaid gate-circuit at its output terminal.
 9. An improved weft feelermechanism claimed in claim 1, wherein reciprocation of said weft feeleris caused by a horizontal swinging of said rocking arm about saidoperator shaft.
 10. An improved weft feeler mechanism claimed in claim9, wherein said reciprocating means comprises a holder bracket fixedlymounted to said operator shaft on which said rocking arm is pivoted atits one end, a link parallel mechanism mounted on said holder bracketconnected with said rocking arm, a connector rod connected to said linkparallel mechanism at its one end, a fixed segment gear freely insertedover said operator shaft, a holder fixedly mounted on said operatorshaft, a bevel gear rotatably mounted on said holder in meshingengagement with said segment gear and an assembly mounted on said holderconnected with the other end of said connector rod for convertingrotation movement of said bevel gear into axial reciprocation of saidconnector rod.
 11. An improved weft feeler mechanism claimed in claim 9,wherein said reciprocating means comprises a holder bracket fixedlymounted to said operator shaft on which said rocking arm is pivoted atits one end, a link parallel mechanism mounted on said holder bracketconnected with said rocking arm, a connector rod connected to said linkparallel mechanism at its one end, a pulse motor fixedly mounted to saidoperator shaft, an assembly connected to said pulse motor and connectedwith the other end of said connector rod for converting rotationmovement of said pulse motor into axial reciprocation of said connectorrod and an electric system for actuating said pulse motor.
 12. Animproved weft feeler mechanism claimed in claim 11, wherein saidelectric system comprises a pulse-oscillator, a gate-circuit connectedto said pulse-oscillator and operating on said pulse motor, a contactswitch periodically operated in synchronism with the crank cycle, aSchmitt-circuit connected to said contact switch, a differentiationcircuit connected to said Schmitt-circuit and a one-shot-multi-vibratorconnected to said differentiation circuit at its input terminal and tosaid gate-circuit at its output terminal.
 13. An improved weft feelermechanism claimed in claim 1, wherein said weft feeler reciprocatesrelative to said free end of said rocking arm.
 14. An improved weftfeeler mechanism claimed in claim 13, wherein said reciprocating meanscomprises an assembly for mounting said weft feeler slidably on saidfree end of said rocking arm, a strand connected to said assembly at itsone end, a rotatable drum fixed to the loom framework on the peripheryof which the other end of said strand is fixed, a rotatable ratchetwheel mounted on said loom framework, a crank mechanism connecting saidratchet wheel with said drum and a pawl disposed to said rocking meansin meshing engagement with said ratchet wheel.